Today I listened to a room with
Synergistic Research's Acoustic ART System. I think it retailed for about $3200. Anyways, the price is fairly out there for what seemed to be some little metal bowls attached to the wall with little wooden pedestals ... to be honest it was very DIY looking, not what I would say looked cool or very decorative, etc.
But the kicker is that when he used them there was something very pleasant about the room in comparison to when he took them away. There was nothing special about the gear in the room, I think it was a Marantz Integrated, plugged into a Synergistic Research Tesla Power Cell and PSB Speakers (don't know the exact models), but I felt I could tell more than a subtle difference which is unusual for me. More of improvement than with the Tesla Power Cell even.
I'd say if the FEQ and HFT products do 1/2 of what the Acoustic ART System does I think it might be worth looking into. Other than DIY traps and such, this is a very cheap way to treat a room. What may be cool is to try some before and after measurements.